Dam.



W FARGQ DAM APPLICATION EEEEEEEEEEEEEEE 8.

bibi/alldllii WILLIAM G. FARGO, Ol" JAGKSGN, nflICHlGAN.

naar.

Specification of Letters Patent.

resented Marcil e, ieee.

Application filed tlune i9, 1908. Serial No. $9,447.

One object `or' the invention is to providev a dam particularly adapted -or streams whose bottoms are of sott material, either of rock or soil.

Another object of the invention resides in the provision of. a dam embodying such characteristics that its base slab will `act both as a cantaliver to distribute pressure `and as a bottom protectionto resist impact and scour of the falling and swiftly moving water. The; apron being built integral with A the dam contributes its weight toward hold- With the above and other objects inview,

the present invention consists in the combination and arrangement of parts hereinafter more fully described, illustrated in the accompanying drawings, and particularly pointed out in the appended claims, it being understood that changes may be made in the formi, proportion, size andcniinor details, without. andeparting from the spirit or sacriieing any of the advantages of the invention.

The accompanying drawing illustrates a transverse sectional view of a dam embodying my invention. i Referring to' the accompanying drawings, itwill bel observed that wall portion l and base slab 2. are of cementitious material and so formed to'la'ct together in compression and shear. rl`hey may be molded in any well known manner, as with construction. joint in compression and shear at 13---14-15-16 117-18 and i9. rEhe base slab is comparativelylong and is directed downstream in direct contradistinction to those structures wherein the base slab isdirected upstream.

The structure vis provided with downwardlydirected teething portions 3. adapted to resist sliding of the dam on its foundation, and nit is also reinforced', the reining feature or' the invention is immateriall in this particular application, and it will be understood that any character of reinforcement may be employed. lzlwever, one of the essential 4features of the invention resides in the approximately vertical face 5. Thus the water pressure will be approximately horizontal l and in cooperating with the downward pressure incident to the dead weight of the masonry, the resultant or combined direction of these two forces acting approximately at right angles will be intermediate between the directions of the two forces and in a direction nearer the greater force of the two. li the two forces were equal the resultant would bisect the angle between the two forces and would be. approximately at an angle of l5 degrees inclining downstream when thewater pressure is horizontal, as indicated along the line 12.

ln order that the resultant or the horizontal water pressure and theldownward pressure resulting from the dead weightv of the structure may be thoroughly understood, it

"will benoted that the resultant of all of the horizontal water pressureais 14,000 lbs,

:per linear fo'ot'of the dam illustrated, at

tlood of 8 feet over the crest, as indicated along the dotted' line 7. The dead load per linear foot is-19,780 lbs. per linear foot of the dam, as indicated by the line 8. The load diagram has its upper boundary at the base of the dam for conveniencevof representation.

The inclined load line 9 indicates that the pressure at downstream edge of thepdam is 900 lbs. per square foot, as indicated at 1,0 and 750 lbs. per square foot at upstream edge, indicated at ll. rlhe intermediate pressure varies uniformly between these two limits and may be found by scaling the load diagram 9 proportionately.` By extending the base slab further downstream the assumed load on the base may bemade uni-- iorm for the section'.

By virtue of vthe approximately vertical face 5 and the con'iparativelylong base slab extending downwardly of the stream, there is such distribution of pressures as to. provide with friction for a firm and safe mounting oi the dam upon its foundation. rlhe base slab, by lreason of its extending downstream, resists -impact and scour of the falling and swiftly moving water, and prevents undermining of the foundation material under the downstream toe. 'lhe metal reinroo forcings and 6 are designed to resist the 1 sliding of the dam on its foundations, the

tension stresses.

With a proper relation between the height ofthe wall of the dam and the depth of water passing over the wall or crest the falling sheet or jet of water approaches the vertical as it strikes the base slab orI apron and its velocity is checked and its energy dissipated to a considerable extentv by impact on the apron. The jet is intended to spring clear of the downstream face of the wall and aeration to prevent vacuum between the sheet and the wall has been found by full size vexperiments to be accomplished by entrained air arising from the eddies on the apron. Therefore the passage of iiood water over this type of dam is essentially diderent from the type of dam having its downstream face curved to secure adherence of the sheet of falling water. p 'o What is claimed is'. f

l. A concrete dam comprising a wall builtin combination with a base slab, the slab extending a comparatively long distance down stream to equally distribute over the base the resultantJ of the horizontal and vertical pressures for any average assumed pressure loading to which the dam is sub jected.

2. A concrete dam reinforced with metal to resist tension stresses and comprising a solid wall built in combination with a solid slab integral therewith, one face of the wall having an approximately vertical face and the base slab forming an apron extending a comparatively long distance down stream.

8. A reinforced concrete dam comprising a wall and a base slab forming an apron disposed on the downstream side of the dam, and a plurality of downwardly' projecting toothings built with the structure to resist apron being integral with the wall and extending down stream a comparatively long distance to receive the falling water in substantially a vertical plane beyond the downstream side of the wall. Y

5 4., A reinforced concrete dam comprising a head wall provided withan approximately Yvertical face to receive the horizontal water pressure land having a base slab forming an apron directed a comparatively long distance down stream, whereby' the apron will resist scour and impact f the water passing over the dam and onto the apron in subn stantially a-vertical plane. .4

5. A reinforced concrete dam comprising a Wall anda base slab, the wall having its 11p-stream face substantially vertical and its downstream facev formed to prevent the falling sheet of water from adhering, to said face and allowing the sheet of water to pound upon the apron beyond said face of the wall and at the natural inclination due to its velocity. l

6. A reinforced concrete dam comprising a solid wall and a base slab integral therewith and frming a cantaliver-apron, the apron being disposed on the down-stream side of the wall and extending a comparatively long distance therefrom and acting to distribute the resultant pressures of the water and the dead weight of the masonry, the apron also resisting scour and impact of the water passing over the dam. l l In testimony whereof I affix my signature, in presence of two witnesses. l

WILLIAM G. FARGO.

' lV-itnesses: 4

G. S. Brasilien', N WNIE KING. 

